Keyword: milankovitch

Ice Ages Blamed on Tilted Earth By Michael Schirber LiveScience Staff Writer posted: 30 March 2005 In the past million years, the Earth experienced a major ice age about every 100,000 years. Scientists have several theories to explain this glacial cycle, but new research suggests the primary driving force is all in how the planet leans. The Earth’s rotation axis is not perpendicular to the plane in which it orbits the Sun. It's offset by 23.5 degrees. This tilt, or obliquity, explains why we have seasons and why places above the Arctic Circle have 24-hour darkness in winter and constant...

The Scientists Are The Bad Guys On March 8, Channel 4 screened The Great Global Warming Swindle, a documentary that branded as a lie the scientific consensus that man-made greenhouse gasses are primarily responsible for climate change. The film was advertised extensively on Channel 4 and repeatedly previewed and reviewed in newspapers. Writing in the Sunday Telegraph, Christopher Booker declared: “Only very rarely can a TV documentary be seen as a pivotal moment in a major political debate, but such was Channel 4's The Great Global Warming Swindle last Thursday. Never before has there been such a devastatingly authoritative account...

If you are the kind of person who worries about the future, this might not make happy reading.Scientists have found that on average mammal species enjoy only 2.5 million years of life before being wiped out because of the Earth's "wobble." They say when the tilt and orbit reach key points it can spark dramatic global cooling - and the last time this happened was 2.6 million years ago. This suggests we are overdue a wave of extinction. However, before you panic, scientists say our planet has changed beyond all recognition in the last 3 million years. The new research...

US Navy Physicist warns of possibly 'several decades of crushing cold temperatures and global famine' By Retired U.S. Navy Physicist and Engineer James A. Marusek 2 Apr 09 – Excerpts: “The sun has gone very quiet as it transitions to Solar Cycle 24. “Since the current transition now exceeds 568 spotless days, it is becoming clear that sun has undergone a state change. It is now evident that the Grand Maxima state that has persisted during most of the 20th century has come to an abrupt end. “(The sun) might (1) revert to the old solar cycles or (2) the...

PARIS (AFP) - The North Pole once had a balmy, sub-tropical sea because of extreme global warming, according to European scientists who have carried out the world's deepest drilling into ancient sediment on the far northern seabed. Cores retrieved from up to 430 metres (1,397 feet) below the seafloor in waters 1,300 metres (4,550 feet) deep show that, for a brief period which occurred around 55 million years ago, the Arctic Ocean was around 20 C (68 F), compared with today's typical average temperature of minus 1.5 C (29.3 F), they said on Tuesday. "It occurred during a period called...

Ice cores unlock climate secrets By Julianna Kettlewell BBC News Online science staff Tiny bubbles of ancient air are locked in the ice Global climate patterns stretching back 740,000 years have been confirmed by a three kilometre long ice core drilled from the Antarctic, Nature reports. Analysis of the ice proves our planet has had eight Ice Ages during that period, punctuated by rather brief warm spells - one of which we enjoy today. If past patterns are followed in the future, we can expect our "mild snap" to last another 15,000 years. The data may also help predict how...

The claim that carbon dioxide (CO2) can increase air temperatures by "trapping" infrared radiation (IR) ignores the fact that in 1909 physicist R.W. Wood disproved the popular 19th Century thesis that greenhouses stayed warm by trapping IR. Unfortunately, many people who claim to be scientists are unaware of Wood's experiment which was originally published in the Philosophical magazine , 1909, vol 17, p319-320. Wood was an expert on IR. His accomplishments included inventing both IR and UV (ultraviolet) photography. Wood constructed two identical small greenhouses. The description implies the type of structure a gardener would refer to as a "coldframe"...

Nanodiamonds found across North America suggest that major climate change could have been cosmically instigatedRoughly 12,900 years ago, massive global cooling kicked in abruptly, along with the end of the line for some 35 different mammal species, including the mammoth, as well as the so-called Clovis culture of prehistoric North Americans. Various theories have been proposed for the die-off, ranging from abrupt climate change to overhunting once humans were let loose on the wilds of North America. But now nanodiamonds found in the sediments from this time period point to an alternative: a massive explosion or explosions by a fragmentary...

Simultaneous warming on Earth and Mars suggests that our planet's recent climate changes have a natural—and not a human-induced—cause, according to one scientist's controversial theory. Earth is currently experiencing rapid warming, which the vast majority of climate scientists says is due to humans pumping huge amounts of greenhouse gases into the atmosphere Mars, too, appears to be enjoying more mild and balmy temperatures. In 2005 data from NASA's Mars Global Surveyor and Odyssey missions revealed that the carbon dioxide "ice caps" near Mars's south pole had been diminishing for three summers in a row. Habibullo Abdussamatov, head of space research...

(Santa Barbara, Calif.) –– In an analysis of the past 1.2 million years, UC Santa Barbara geologist Lorraine Lisiecki discovered a pattern that connects the regular changes of the Earth's orbital cycle to changes in the Earth's climate. The finding is reported in this week's issue of the scientific journal Nature Geoscience. Lisiecki performed her analysis of climate by examining ocean sediment cores. These cores come from 57 locations around the world. By analyzing sediments, scientists are able to chart the Earth's climate for millions of years in the past. Lisiecki's contribution is the linking of the climate record to...

Sun's fickle heart may leave us cold 25 January 2007 From New Scientist Print Edition.Stuart Clark There's a dimmer switch inside the sun that causes its brightness to rise and fall on timescales of around 100,000 years - exactly the same period as between ice ages on Earth. So says a physicist who has created a computer model of our star's core. Robert Ehrlich of George Mason University in Fairfax, Virginia, modelled the effect of temperature fluctuations in the sun's interior. According to the standard view, the temperature of the sun's core is held constant by the opposing pressures of...

A chain of past natural events may hold lessons for the futureScientists still puzzle over how Earth emerged from its last ice age, an event that ushered in a warmer climate and the birth of human civilization. In the geological blink of an eye, ice sheets in the northern hemisphere began to collapse and warming spread quickly to the south. Most scientists say that the trigger, at least initially, was an orbital shift that caused more sunlight to fall across Earth's northern half. But how did the south catch up so fast? In a review paper published this week in...

1975 Newsweek article on global cooling. http://www.globalclimate.org/Newsweek.htm FROM Newsweek April 28, 1975 The Cooling World There are ominous signs that the Earth’s weather patterns have begun to change dramatically and that these changes may portend a drastic decline in food production– with serious political implications for just about every nation on Earth. The drop in food output could begin quite soon, perhaps only 10 years from now. The regions destined to feel its impact are the great wheat-producing lands of Canada and the U.S.S.R. in the North, along with a number of marginally self-sufficient tropical areas – parts of India,...

Variability of the sun’s irradiance, Global Warming Water Experts Find Earth’s Warming, Rainfall Linked to Sun By Dennis T. Avery, Hudson Institute Tuesday, July 24, 2007 A team of water experts says the pattern of droughts and floods in South Africa shows our global warming was triggered by the variability of the sun’s irradiance rather than by human-emitted CO2. They say variations in South African rainfall patterns are keyed to periodic reversals of the sun’s magnetic field—and to the constantly changing distance between the sun and the earth as both move through space. In South Africa, alternate 11-year sunspot...

Carbon dioxide did not cause the end of the last ice age, a new study in Science suggests, contrary to past inferences from ice core records. “There has been this continual reference to the correspondence between CO2 and climate change as reflected in ice core records as justification for the role of CO2 in climate change,” said USC geologist Lowell Stott, lead author of the study, slated for advance online publication Sept. 27 in Science Express. “You can no longer argue that CO2 alone caused the end of the ice ages.” Deep-sea temperatures warmed about 1,300 years before the tropical...

Posted on January 24, 2011 by Anthony Watts Precession of Earth's rotational axis due to the tidal force raised on Earth by the gravity of the Moon and Sun. - Image via NASA - click for moreby Dr. Martin HertzbergAs the saying goes:“If all you have in your hand is a hammer, then everything looks like a nail”.It is hopeless to expect that Hansen could possibly analyze data objectively – all he has in his head is “CO2 climate forcing” and everything else has to be “forced” into that ridiculous paradigm. It makes no difference to him that the predictions...

This is a follow up posting to Younger Dryas -The Rest of the Story!Guest post by Don J. Easterbrook Dept. of Geology, Western Washington University.The Younger Dryas was a period of rapid cooling in the late Pleistocene 12,800 to 11,500 calendar years ago. It followed closely on the heels of a dramatically abrupt warming that brought the last Ice Age to a close (17,500 calendar years ago), lasted for about 1,300 years, then ended as abruptly as it started. The cause of these remarkably sudden climate changes has puzzled geologists and climatologists for decades and despite much effort to find...

The Intergovernmental Panel on Climate Change (IPCC) science and its promotion involves selection of only material that supports the hypothesis that human CO2 is causing warming and latterly climate change. It is used in everything from tree ring samples chosen to create the hockey stick, to omission of the Milankovitch Effect, and the role of cosmic rays in the formation of low cloud from IPCC computer models.There’s a similar pattern of selective reporting about weather events. People are inundated with reports giving the impression that what is happening is worse then ever before, unusual and therefore due to human activities....

WASHINGTON, D.C., December 22, 2006 (LifeSiteNews.com) - The general warming of global temperatures in recent decades appears to mostly be the result of a regular, sunspot induced climate cycle that has been occurring roughly every 1500 years for at least the past one million years. Climate physicist S. Fred Singer and Dennis Avery, senior fellow at the Hudson Institute, discussed the substantial evidence for their new book "Unstoppable Global Warming: Every 1500 Years," at a Hudson Institute book forum in Washington, D.C. last month. The book is said to make a very powerful case that the current climate trends...

When do ice ages begin? In June, of course. Analysis of Antarctic ice cores led by Kenji Kawamura, a visiting scientist at Scripps Institution of Oceanography, UC San Diego, shows that the last four great ice age cycles began when Earth’s distance from the sun during its annual orbit became great enough to prevent summertime melts of glacial ice. The absence of those melts allowed buildups of the ice over periods of time that would become characterized as glacial periods. Results of the study appear in the Aug. 23 edition of the journal Nature. Jeff Severinghaus, a Scripps geoscientist and...

· Meltwater plays only small role in glacier flow · Study casts doubt on 'lubrication' theory Fears that the rapid draining of water from the top of Greenland's ice sheet may be contributing to the rise of global sea levels have been allayed by new research. Though scientists confirmed that the water can drain away faster than Niagara Falls, it did not seem to accelerate the movement of the ice sheet into the ocean as previously thought. Receding ice sheets are of major concern to climate scientists because the melting water could lead to a rise in sea levels. In...

In the early 20th century, Milutin Milankovitch, a leading astronomer and climatologist of the time, proposed that the Earth's ice-age cycles could be predicted because they correspond directly with routine changes in the Earth's orbit and its tilt over cycles of tens of thousands of years. Because of these changes, there are predictable variations in the amount of solar radiation striking the Earth's surface. Milankovitch argued that low levels of summer radiation permit snow to accumulate as permanent ice, while high levels of solar radiation melt snow and ice. It all seemed so clean and simple. And indeed the hypothesis...

According to a new paper by Gerald E. Marsh (PDF), they do. If true, this has great implications for the debate over whether humans are causing global warming, or whether it is a natural phenomenon. More about Marsh here.Marsh says that changes in carbon dioxide levels simply canâ€™t account for the differences in temperatures between interglacials, while changes in cloud cover caused by a change in galactic cosmic ray flux can.Changes in cosmic rays The conventional global warming explanation for the Ice Ages and interglacial periods (we are in one right now), is that a change in the Earthâ€™s orbit...

I wrote this about six months ago, but never posted it. The version I've posted here doesn't have images. A link to an html version with images is here and a PDF version of the article is hereEnjoy. Is global warming caused by human activity? Paul Drallos, Ph.D. (Physics) A great number of facts and declarations are often presented with regard to global warming and Mankind's role in it. Most of these assertions are derived from the following clear and simple line of reasoning: Fact: CO2 is a greenhouse gas whose presence in the atmosphere can cause Earth's temperature...

From the Universitat Autonoma de Barcelona a suggestion that ocean CO2 sequestration is driven by iron laden dust blown into the oceans that cause phytoplankton blooms, resulting in the ocean as a CO2 sink. It’s another take on the proposed experiment from a couple of years ago where a researcher wanted to drop a barge of powdered iron into the ocean to watch what happens. It was actually tried, and was reported to be a failure. Dust in the Mediterranean - Image NASA Climate in the past million years determined greatly by dust in the Southern OceanA group of scientists...

Nicola Scafetta sent me this paper yesterday, and I read it with interest, but I have a number of reservations about it, not the least of which is that it is partially based on the work of Landscheidt and the whole barycentric thing which gets certain people into shouting matches. Figure 9 looks to be interesting, but note that it is in generic units, not temperature, so has no predictive value by itself.Fig. 9. Proposed solar harmonic reconstructions based on four beat frequencies. (Top) Average beat envelope function of the model (Eq. (18)) and (Bottom) the version modulated with a...

The other day I went to a global warming presentation delivered by my friend, Mason Wilson (retired Professor Emeritus from the University of Rhode Island, College of Engineering). I was so impressed by the information he presented and by his organization of the material that I invited him to post it on my blog. He starts by explaining the difference between short range weather forecasting, based on real-time data – and longer range forecasting, based primarily on extrapolating historical data into the future. Next he points out the significance of the historical record of climate data on which there should...

Editor's Note: This story embargoed for release until 2 pm ET Wednesday, October 17, 2001, to coincide with publication in the journal Nature.) COLUMBUS, Ohio - An international team of scientists reported this week that a rock core drilled from the seafloor off the coast of Antarctica is the first to show cyclic climate changes in polar regions that are linked to cores taken from the ocean bottom in both temperate and tropical zones. These records show ice sheet advances and retreats that match Milankovitch cycles - variations in the Earth's orbit around the sun, in the tilt of the ...

What do month-to-month changes in temperature have to do with century-to-century changes in temperature? At first it might seem like not much. But in a report published in this week’s Nature, scientists from the Woods Hole Oceanographic Institution (WHOI) have found some unifying themes in the global variations of temperature at time scales ranging from a single season to hundreds of thousands of years. These findings help place climate observed at individual places and times into a larger global and temporal context. “Much of the work went into assembling the different types of records needed to study such diverse time...